1. Field of the Invention
The present invention relates to a display device, and more particularly, to an energy recovery circuit of a display device, which provides a driving voltage to a display panel.
2. Discussion of the Prior Art
Among various display devices, a plasma display panel(PDP) is a display device using a gas discharge technology. The PDP can be divided into two types, i.e., an alternating current type and a direct current type. The PDP of the direct current type uses the surface discharge which occurs on the surface of a dielectric substance when an electrode is coated with a dielectric substance.
In the PDP of the direct current type, great losses of the power occur because of a driving pulse with a high frequency and any charge/discharge caused by a high driving voltage. In order to minimize this power loss, an energy recovery circuit is additionally provided to a driving circuit of the PDP.
The energy recovery circuit reuses the ineffectual energy as a driving voltage for a next discharging stage, by recovering the energy which is ineffectually generated in the display panel(i.e., ineffectual energy).
FIG. 1 is a diagram illustrating a typical energy recovery circuit in accordance with the prior art. As shown in FIG. 1, the energy recovery circuit of the prior art includes first and third switches S1 and S3 connected to an energy recovery capacitor Cs in parallel, a second switch S2 for providing a sustain voltage Vs to a display panel, and a fourth switch S4 for providing a ground voltage(GND) to the display panel.
The method of driving the energy recovery circuit of the prior art shown in FIG. 1 will be described below.
First, the first switch S1 is turned on to provide the voltage charged in the energy recovery capacitor Cs to a display panel, and a second switch S2 is turned on to provide the sustain voltage Vs to the display panel as well.
Then, the third switch S3 is turned on to recharge the energy recovery capacitor Cs with a portion of the voltage provided to the display panel. Lastly, a fourth switch S4 is turned on to ground the voltage of the display panel.
The energy recovery circuit of the prior art, however has the following disadvantages. In the energy recovery circuit of the prior art, power consumption increases because of a high voltage (Vs) required for maintaining the display panel to a sustain voltage level.
Also, because the switch devices suitable for such high voltage are required in the prior art, a cost for producing the circuit is extremely high.